feat: implement User Story 2 - Search and Discovery (P2)

Implemented 12 new MCP tools for search and knowledge graph navigation:

Search Tools (2):
- obsidian_search: Content search with folder filtering and case sensitivity
- obsidian_search_with_context: Search with surrounding context lines

Link Tools (5):
- obsidian_get_backlinks: Show incoming links to a note
- obsidian_get_outgoing_links: Show outgoing links from a note
- obsidian_list_unresolved_links: Find broken wikilinks
- obsidian_list_deadends: Find notes with no outgoing links
- obsidian_list_orphans: Find notes with no incoming links

Tag & Alias Tools (3):
- obsidian_list_tags: List all tags with optional counts
- obsidian_get_tag_info: Detailed tag usage information
- obsidian_list_aliases: List note aliases

Property Discovery Tools (2):
- obsidian_list_properties: List all vault properties
- obsidian_get_property_count: Get property usage counts

New files created:
- src/tools/search.ts (2 tools)
- src/tools/links.ts (5 tools)
- src/tools/tags-aliases.ts (3 tools)
- src/tools/properties.ts (2 tools)

Updated:
- src/tools/index.ts: Register all new tool modules
- src/validation/schemas.ts: Enhanced searchSchema with new parameters
- manifest.json: Added 12 new tools to tools array (21 total)
- tasks.md: Marked T046-T063 complete (18 tasks)

Build: ✅ 0 errors
Validation: ✅ Manifest passes
Total tools: 21 (9 US1 + 12 US2)
Tasks complete: 70/167 (41.9%)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/tools/properties.ts

@@ -0,0 +1,90 @@
+/**
+ * Properties Tools
+ * User Story 2 (P2): Property discovery and querying
+ */
+
+import { ObsidianMCPServer, createToolHandler } from '../server.js';
+import { executeObsidianCommand } from '../cli/executor.js';
+import { formatForMCP, parseOutput } from '../cli/parser.js';
+import { handleCLIResult } from '../utils/error-handler.js';
+import { logger } from '../utils/logger.js';
+import { sanitizeParameters } from '../validation/sanitizer.js';
+
+/**
+ * Register all property tools for discovery
+ */
+export async function registerPropertyDiscoveryTools(server: ObsidianMCPServer): Promise<void> {
+  logger.info('Registering property discovery tools');
+
+  // T057: List properties tool (vault-wide)
+  server.registerTool(
+    'obsidian_list_properties',
+    'List all properties used in the vault. Shows property keys and optionally their types and usage counts.',
+    { type: 'object', properties: {} },
+    createToolHandler(
+      'List all properties in vault',
+      { type: 'object', properties: {} },
+      async (args) => {
+        const sanitized = sanitizeParameters(args as any) as any;
+
+        const cmdArgs: string[] = ['list-properties'];
+        if (sanitized.counts) cmdArgs.push('--counts');
+        if (sanitized.types) cmdArgs.push('--types');
+        if (sanitized.format) cmdArgs.push('--format', sanitized.format as string);
+
+        const result = await executeObsidianCommand('property', cmdArgs);
+        handleCLIResult(result, { operation: 'list_properties' });
+
+        const format = sanitized.format || 'text';
+        const parsedData = parseOutput(result.stdout, format);
+
+        return {
+          content: [
+            {
+              type: 'text',
+              text: formatForMCP(parsedData, format),
+            },
+          ],
+        };
+      }
+    )
+  );
+
+  // T058: Get property count tool
+  server.registerTool(
+    'obsidian_get_property_count',
+    'Get the usage count for a specific property across the vault. Shows how many notes use this property.',
+    { type: 'object', properties: {} },
+    createToolHandler(
+      'Get property usage count',
+      { type: 'object', properties: {} },
+      async (args) => {
+        const sanitized = sanitizeParameters(args as any) as any;
+
+        if (!sanitized.property) {
+          throw new Error('Property parameter is required');
+        }
+
+        const cmdArgs: string[] = ['property-count', sanitized.property as string];
+        if (sanitized.format) cmdArgs.push('--format', sanitized.format as string);
+
+        const result = await executeObsidianCommand('property', cmdArgs);
+        handleCLIResult(result, { operation: 'property_count', property: sanitized.property });
+
+        const format = sanitized.format || 'text';
+        const parsedData = parseOutput(result.stdout, format);
+
+        return {
+          content: [
+            {
+              type: 'text',
+              text: formatForMCP(parsedData, format),
+            },
+          ],
+        };
+      }
+    )
+  );
+
+  logger.info('Property discovery tools registered', { count: 2 });
+}